In the medical field, leads are used with a wide variety of medical devices. For example, leads are commonly implemented to form part of implantable cardiac pacemakers that provide therapeutic stimulation to the heart by delivering pacing, cardioversion or defibrillation pulses. The pulses can be delivered to the heart via electrodes disposed on the leads, e.g., typically near distal ends of the leads. In that case, the leads position the electrodes with respect to various cardiac locations so that the pacemaker can deliver pulses to the appropriate locations. Leads are also used for sensing purposes, or both sensing and stimulation purposes.
In addition, leads are used in neurological devices such as deep-brain stimulation devices, and spinal cord stimulation devices. In that case, the leads are stereotactically probed into the brain to position electrodes for deep brain stimulation. Leads are also used with a wide variety of other medical devices, including devices that provide muscular stimulation therapy, devices that sense chemical conditions in a patient's blood, and the like. In short, medical leads can be used for sensing purposes, stimulation purposes, or both.
One challenge in implementing medical leads in an implantable medical device (IMD) is the electrical coupling between a respective lead and sensing or stimulation circuitry of the IMD. An IMD typically includes one or more leads, a housing that houses circuitry of the IMD, and a connector module that couples the leads to the circuitry. In particular, the connector module typically includes electrical contact structures for coupling a medical lead to circuitry within the housing of the IMD so that therapeutic simulation can be provided through the lead, or sensed conditions can be recorded by the circuitry. In addition, the connector module includes seal rings that provide hermetic barriers between the electrical contact structures. The leads are inserted into the connector module in order to achieve such electrical coupling between the lead and the circuitry of the IMD.
Various connection standards have been developed in order to ensure electrical connections between the IMD circuitry and the medical lead are acceptable, while also maintaining a sufficient hermetic seal between the connector module and the lead to avoid ingress of body fluids into the housing. These standards continue to evolve in order to accommodate new lead designs, such as in-line leads that include a plurality of electrodes and a plurality of electrical contact areas disposed along the lead.
There remains a need for lead connector configurations that are simple to use and inexpensive to fabricate. Improved simplicity can help ensure that physicians can make the electrical connections during implantation of the IMD with minimal concern for electrical coupling malfunction. Reduced fabrication expense can help ensure that patient costs associated with an IMD are minimized.